Paper products are used for a variety of purposes. Paper towels, facial tissues, toilet tissues, and the like are in constant use in modern industrialized societies. The large demand for such paper products has created a demand for improved versions of the products. If the paper products such as paper towels, facial tissues, toilet tissues, and the like are to perform their intended tasks and to find wide acceptance, they must possess certain physical characteristics. Among the more important of these characteristics are strength, softness, and absorbency.
Strength is the ability of a paper web to retain its physical integrity during use.
Softness is the pleasing tactile sensation consumers perceive when they use the paper for its intended purposes.
Absorbency is the characteristic of the paper that allows the paper to take up and retain fluids, particularly water and aqueous solutions and suspensions. Important not only is the absolute quantity of fluid a given amount of paper will hold, but also the rate at which the paper will absorb the fluid.
Through-air drying papermaking belts comprising a reinforcing structure and a resinous framework are described in commonly assigned U.S. Pat. No. 4,514,345 issued to Johnson et al. on Apr. 30, 1985; U.S. Pat. No. 4,528,239 issued to Trokhan on Jul. 9, 1985; U.S. Pat. No. 4,529,480 issued to Trokhan on Jul. 16, 1985; U.S. Pat. No. 4,637,859 issued to Trokhan on Jan. 20, 1987; U.S. Pat. No. 5,334,289 issued to Trokhan et al on Aug. 2, 1994. The foregoing patents are incorporated herein by reference for the purpose of showing preferred constructions of through-air drying papermaking belts.
The paper produced on the belts disclosed in these patents is characterized by having two physically distinct regions: a continuous network region having a relatively high density and a region comprised of a plurality of domes dispersed throughout the whole of the network region. The domes are of relatively low density and relatively low intrinsic strength compared to the network regions. Such belts have been used to produce commercially successful products such as Bounty paper towels and Charmin Ultra toilet tissue, both produced and sold by the instant assignee.
U.S. Pat. No. 5,245,025 issued to Trokhan et al. on Sep. 14, 1993; and U.S. Pat. No. 5,527,428 issued to Trokhan et al. on Jun. 18, 1996, which are incorporated herein by reference, disclose a cellulosic fibrous structure comprising a plurality of regions: an essentially continuous first region of a relatively high basis weight; a second region of a relatively low or zero basis weight and circumscribed by and adjacent the first region; and a third region of an intermediate basis weight and juxtaposed with the second region. A forming belt for producing such a paper comprises a patterned array of discrete protuberances joined to a reinforcing structure. Annuluses between adjacent protuberances provide space into which papermaking fibers may be deflected to form the first region. In addition, each individual protuberance may have an aperture therein. The apertures in the individual protuberances also provide space into which the papermaking fibers may deflect to form the third region.
Still, a search for improved products has continued.
It may be desirable in some instances to produce cellulosic webs having "angled" cross-sectional patterns, i.e., the webs which--when viewed in the cross-section--have the domes extending from an essentially continuous network region such that the domes are not generally perpendicular, but instead are acutely angled, relative to the plane of the network region. Particularly, such "angled" domes may improve the web's softness due to increased collapsibility of the angles domes, compared to the perpendicularly upstanding domes. In addition, it is believed that such angled structures will possess an ability to direct absorbed fluids in a desired (and predetermined) direction, based on the specific (and also predetermined) orientation of the domes in the web. Such properties may be very beneficial in a variety of disposable products.
Therefore, it is an object of the present invention to provide a cellulosic web having at least two regions: an essentially continuous region and a region comprising a patterned array of discrete domes or knuckles extending from the essentially continuous region such that the axes of the domes or knuckles and the general plane of the essentially continuous region form acute angles therebetween.
It is another object of the present invention to provide a process of making such cellulosic webs.
It is still another object of the present invention to provide a papermaking belt for producing such cellulosic webs.
It is further object of the present invention to provide a process of making such papermaking belt.